Multi-hop Way Research Articles

Enhancing Potential Re-Finding in Personalized Search With Hierarchical Memory Networks

The goal of personalized search is to tailor the document ranking list to meet user's individual needs. Previous studies showed users usually look for the information that has been searched before. This is called re-finding behavior which is widely explored in existing personalized search approaches. However, most existing methods for identifying re-finding behavior focus on simple lexical similarities between queries. In this paper, we propose a personalized framework based on hierarchical memory networks (MN) to enhance the identification of the potential re-finding behavior. Specifically, we explore the potential re-finding behaviors of users from two dimensions. (1) Granularity dimension. The framework carries out re-finding identification with external memories from word, sentence, and session levels. (2) Query intent dimension. Query-based re-finding and document-based re-finding are taken into account to cover user's different query intents. To enhance the interaction between different memory slots, we optimize the <inline-formula><tex-math notation="LaTeX">$READ$</tex-math></inline-formula> operation of MN with two strategies that utilize the information in memory in a multi-hop way. Endowed with these memory networks, we can enhance user's potential re-finding behaviors and build a fine-grained user model dynamically. Experimental results on two datasets have a significant improvement over baselines, and the optimized <inline-formula><tex-math notation="LaTeX">$READ$</tex-math></inline-formula> operation shows better performance.

Optimal vs rotation heuristics in the role of cluster-head for routing in IoT constrained devices

Wireless Sensor Networks (WSNs) are crucial for implementing the Internet of Things (IoT) vision. A WSN can include distributed devices that can be battery powered, have a small amount of memory, have limited CPU processing capabilities and limited transmission range. WSNs are categorised into two main types that are homogeneous and heterogeneous. Homogeneous WSNs are composed of nodes that are all equal while heterogeneous ones are composed of nodes that can have different transmission rate and different initial energy. Collecting data in an energy efficient manner is one of the main goals when building wireless sensor networks since devices are battery powered and battery replacement can be difficult or impossible to be performed. Clustering protocols are one of the main approaches that have been used in order to collect data in an energy efficient way. A clustering protocol groups nodes into a set of clusters. Each cluster has a representative node that is referred to as Cluster Head (CH). This collects data from its cluster members and forwards them to an external Base Station, possibly in a multi-hop way among cluster heads. A rotation strategy for electing the cluster head is often used together with clustering in order to prolong the network lifetime. Rotation eliminates the overhead traffic that is needed for leader election and cluster formation since the old cluster heads directly designate new ones. In this work, we describe an Optimum Rotation Scheduling (ORS) that uses Integer Linear Programming in order to find the optimum rotation strategy. ORS assumes the WSN clusters are already formed by using some clustering protocol. A novel integer linear programming formulation is then used in order to define a cluster head rotation that produces the optimum cluster lifetime. Comparisons with existing heuristics and the provided optimum are then shown and discussed by means of extended simulations involving both homogeneous and heterogeneous WSNs.

Cluster Head Selection and Optimal Multipath detection using Coral Reef Optimization in MANET Environment

Mobile Ad-hoc Network (MANET) data transfer between nodes in a multi-hop way offers a wide variety of applications. The dynamic feature of ad hoc network mobile nodes is primarily influenced by safety issues, which limit data forwarding rate in multipath routing. As a supplementary method to improve safe data delivery in a MANET, this paper propose and analyse the cluster head (CH) selection and optimum multipath scheme. The CHs are chosen based on the possibility values of each node in MANET, which are considered from the residual energy of each node. During the present phase, the total remaining node energy is used to calculate the mean energy of the entire network. The most likely nodes are picked as the CH, which gathers packets from the cluster members through multi-hop communication. The fundamental idea is to partition a top-secret communication into several shares and then forward the shares via numerous routes to the destination. The Coral Reef Optimization method is used in this work to perform optimum multipath routing. The thorough simulation findings validate the feasibility and efficacy of the suggested strategy in comparison to Butterfly optimization algorithm (BA), Whale Optimization algorithm (WOA) and BAT algorithm techniques.

An Algorithm with Efficiently Collecting and Aggregating Data for Wireless Sensor Networks

Due to the resource constraint, in wireless sensor network, the node processing ability, wireless bandwidth and battery capacity and other resources are scarcer. For improving the energy efficient and extend the lifetime of the network, this paper proposes a novel algorithm with the distributed and energy-efficient for collecting and aggregating data of wireless sensor network. In the proposed protocol, nodes can autonomously compete for the cluster head based on its own residual energy and the signal strength of its neighbouring nodes. To reduce the energy overhead of cluster head nodes, with a multi-hop way among cluster heads, the collected data from cluster heads is sent to a designated cluster head so as to further send these data to a base station. For improving the performance of the proposed protocol, a new cluster coverage method is proposed to fit the proposed protocol so that when the node density increases, network lifetime can be increased linearly as the number of nodes is increased. Simulations experiments show that network lifetime adopting the proposed protocol is sharply increased. And, the proposed protocol makes all the nodes die (network lifetime is defined as the death of last one node) in the last 40 rounds so that networks adopting the proposed protocol have higher reliability than networks adopting compared protocols.

AHKM: An improved class of hash based key management mechanism with combined solution for single hop and multi hop nodes in IoT

The extensive growth of the Internet of Things (IoT) devices leads to the evolution of the broad range of smart applications in numerous fields such as smart home, wearable, education, agriculture, health care, transportation and many more. But security for IoT devices is still a challenging issue as many attacks are possible in the environment. Therefore strong security requirements are an important concern to safeguard the IoT smart devices. The sensor network has to select an efficient encryption algorithm to provide secure communication between sensor nodes. The basic requirement for encrypted communication is key establishment and distribution. The currently available key management process involves large computational overhead, energy consumption, and delay. This makes the network inefficient since sensor nodes have limited bandwidth capacity. The main aim of this paper is to establish a strong key management mechanism to overcome the issues in the current cluster based key management technologies. The work proposed a secure hash key-based key management scheme for the cluster based network environment. The proposed scheme considers the two-level verification process, a one-hop way for the nodes within the cluster and a multi-hop way for the nodes outside the transmission range. The work done is examined through simulation by varying the number of malicious nodes in the environment. The result shows that the rate of packet loss has been reduced when compared with a one-hop way of key management solution. The proposed work also enhances the performance of the network by lowering the energy, computational overheads, and delay.

A geographical hierarchy greedy routing strategy for vehicular big data communications over millimeter wave

As the autonomous and intelligent driving technologies rapidly develop, vehicles are equipped with more sensors and produce more data. To cope with the challenge of big data, millimeter wave (mmWave) can achieve data rates of up to multiple gigabits per second. Though mmWave communications can provide wide bandwidths, mmWave is susceptible to blockage due to its poor diffraction capability and its high penetration loss. To overcome the limited communication range for vehicular applications in wide areas, a routing strategy is required to relay data in a multi-hop way. In this work, we propose a geographical hierarchy greedy routing algorithm for inter-vehicle mmWave communications. Also, we evaluate the channel characteristics and the throughput performance of mmWave working at 60 GHz. The proposed routing strategy makes use of geographical information for relay determination while maintaining the high throughput and ensuring the channel stability of mmWave. Based on the simulation results, it is found that mmWave is promising for the future big data vehicular applications.

A multi-tier based clustering framework for scalable and energy efficient WSN-assisted IoT network

The effectiveness of wireless sensor network (WSN) in Internet of Thing (IoT) based large scale application depends on the deployment method along with the routing protocol. The sensor nodes are an important component of WSN-assisted IoT network running on limited and non-rechargeable energy resource. The performance of WSN-assisted IoT is decreased, when network is deployed at large area. So, developing robust and energy-efficient routing protocol is a challenging task to prolong the network lifetime. In contrast to the state-of-the-art techniques this paper introduces Scalable and energy efficient routing protocol (SEEP). SEEP leverages the multi-hop hierarchical routing scheme to minimize the energy consumption. To achieve scalable and energy efficient network, SEEP employs a multi-tier based clustering framework. The network area in SEEP is divided into various zones with the help of proposed subarea division algorithm. The number of zones in the network are increased as the network size increases to avoid long-distance communication. Every zone is divided into certain number of clusters (sub-zones) and the number of clusters are increased towards the base station, whereas the zone width is decreased. In every cluster, some of the optimal nodes are promoted as a Relay Node (RN) and Cluster Head (CH). Normal nodes send their sensed data to the base station via local RN and CH in a multi-hop way. Furthermore, propose protocol provides a trade-off between distance and energy to prolong the network lifetime. In the proposed framework, static and mobile scenarios have been considered by applying Random walk and Random waypoint model for node mobility in simulation to make it more realistic as the various application of WSN-assisted IoT. The effectiveness of SEEP is examined against LEACH, M-LEACH, EA-CRP, TDEEC, DEEC, SEP, and MIEEPB, and result indicates that SEEP performs better for different network metrics: network lifetime, scalability, and energy efficiency.

HETRP: High Energy Efficient Trustable Routing Protocol for Wireless Sensor Network

Wireless sensor network environment based on limited resources technology. Energy is one of the most significant resources in such systems, so ideal utilization of energy is essential. A high energy efficient with trustable routing-protocol for Wireless_Sensor_Networks covered under this_paper. The protocol is trustworthy as far as data conveyance at the Base_Station. We assumed about portability in sensor nodes and in the base station. The proposed protocol depends on the cluster and hierarchical routing protocols. All clusters comprises of unique cluster-head-node and two-deputy-cluster-head-nodes, and several normal sensor-nodes. The cluster-head panel model introduced to optimize the re-clustering time and energy prerequisites. As consider the protocol trustworthiness, it lays finest exertion to guarantee a predetermined level of performance at the base-station. Contingent upon the network topology, transmit data from cluster head node to base station that done either by direct or indirect i.e. multi-hop way. Also, substitute ways are utilized for data transmission between a cluster head node and the base station. Thorough NS2 simulation-results delineate energy-efficiency, throughput, and delayed-lifetime of sensor-nodes affected by the proposed-protocol.

A New Method for Multi-hop Communication Over Bluetooth in Smartphones

In this investigation, we built up a versatile application that gives scatternet organize setup utilizing Bluetooth interface on advanced mobile phones running Android Operating System to meet the communication needs of individuals, where there is no Central Access Point, the Internet or physical framework on the earth. The messages transmitted on the system are transmitted shared in a multi-hop way. Each gadget that joins the system can act both server and shopper jobs. Every gadget likewise fills in as a switch. Companions partaking in the system can take in the current condition of the system from the gadget to which they are connected as a tree structure. Along these lines, each associate takes in the current structure of the system. In the meantime, a calculation was created and executed to spread the data of the recently included gadget to all reporters the system. The created application design is planned to be utilized as an elective specialized strategy in a wide range of outside and indoor situations, in regions where normal conditions, for example, mines are hard to impart, cataclysmic event territories, protect tasks, digital fear monger assaults and running remote sensor systems.

A Routing Optimization Based on Cross-Layer Design for Wireless Multimedia Sensor Networks (WMSNs)

Multimedia applications are routed from source nodes via neighboring nodes to a sink in Wireless Multimedia Sensor Networks (WMSNs). However, the existing routing protocols in the WMSNs do not fulfill the quality of service (QoS) constraint yet for multimedia transmission. The WMSNs have specific characteristics such as multi-hop way, limited node capability and varying bandwidth, which can affect the quality of service of multimedia applications during the routing process. The best quality of service (QoS) is required by the multimedia applications consisting of high throughput, low end-to-end delay and low packet drop rate. A routing optimization based on the cross-layer design is proposed for multimedia transmission in the WMSNs. The cross-layer design utilizes H.264/Scalable Video Coding (SVC) and IEEE 802.11e Enhanced Distributed Channel Access (EDCA) and has been implemented in Network Simulator 2 (NS2) simulation. The NS2 simulation indicates that the H.264/SVC video application has an average delay of 0.02 sec. Thus, the routing optimization has accomplished to deliver multimedia application successfully via Wireless Multimedia Sensor Network (WMSN).

LEACH Routing Protocol Based on Wireless Sensor Networks

Wireless sensor network (WSN) is a new research area in modern communications networks. Composed by many stationary or mobile sensor nodes, it constitutes a wireless network through selforganizing and multi-hop way. A sensor network system includes sensor node (end device), sink node (sink) and coordinator node (coordinator). The routing protocol of WSN is to find the optimal route between the source node and destination node. Its primary goal is to improve the quality of network service and achieve a fair and rational use of resources such as network bandwidth for various network nodes and terminals. The work focused on the typical and successful representative in the

An energy efficient MAC protocol for multi-hop swallowable body sensor networks.

Swallowable body sensor networks (BSNs) are composed of sensors which are swallowed by patients and send the collected data to the outside coordinator. These sensors are energy constraint and the batteries are difficult to be replaced. The medium access control (MAC) protocol plays an important role in energy management. This paper investigates an energy efficient MAC protocol design for swallowable BSNs. Multi-hop communication is analyzed and proved more energy efficient than single-hop communication within the human body when the circuitry power is low. Based on this result, a centrally controlled time slotting schedule is proposed. The major workload is shifted from the sensors to the coordinator. The coordinator collects the path-loss map and calculates the schedules, including routing, slot assignment and transmission power. Sensor nodes follow the schedules to send data in a multi-hop way. The proposed protocol is compared with the IEEE 802.15.6 protocol in terms of energy consumption. The results show that it is more energy efficient than IEEE 802.15.6 for swallowable BSN scenarios.

Different Types of Attacks and Detection Techniques in Mobile Ad Hoc Network

A Mobile Ad-Hoc Network (MANET) is a collection of mobile nodes (stations) communicating in a multi hop way without any fixed infrastructure such as access points or base stations. MANET has not well specified defense mechanism, so malicious attacker can easily access this kind of network. In this paper we investigate different types of attacks which are happened at the different layers of MANET after that we discuss some available detection techniques for these attacks. To our best knowledge this is the first paper that studies all these attacks corresponding to different layers of MANET with some available detection techniques.

Energy-efficient routing control algorithm in large-scale WSN for water environment monitoring with application to Three Gorges Reservoir area.

The typical application backgrounds of large-scale WSN (wireless sensor networks) for the water environment monitoring in the Three Gorges Reservoir are large coverage area and wide distribution. To maximally prolong lifetime of large-scale WSN, a new energy-saving routing algorithm has been proposed, using the method of maximum energy-welfare optimization clustering. Firstly, temporary clusters are formed based on two main parameters, the remaining energy of nodes and the distance between a node and the base station. Secondly, the algorithm adjusts cluster heads and optimizes the clustering according to the maximum energy-welfare of the cluster by the cluster head shifting mechanism. Finally, in order to save node energy efficiently, cluster heads transmit data to the base station in single-hop and multihop way. Theoretical analysis and simulation results show that the proposed algorithm is feasible and advanced. It can efficiently save the node energy, balance the energy dissipation of all nodes, and prolong the network lifetime.

Analysis of Security Threats and Vulnerabilities in Mobile Ad Hoc Network (MANET)

A Mobile Ad-Hoc Network (MANET) is a collection of mobile nodes communicating in a multi hop way without any fixed infrastructure such as access points or base stations. Mobile ad hoc networks have several advantages over the traditional wired networks, on the other sides they have a unique set of challenges like MANETs face challenges in secure communication, mobile nodes without adequate protection are easy to compromise, static configuration may not be adequate for the dynamically changing topology in terms of security solution and finally, lack of cooperation and constrained capability is common in MANET. MANET has not well specified defense mechanism, so malicious attacker can easily access this kind of network. Although security issues in Mobile Ad-hoc Networks (MANETs) have been a major focus in the recent years, the development of most secure schemes for these networks has not been entirely achieved till now. This research paper will provide an overview about the security issues and available detection techniques in Mobile ad hoc networks. In this research paper, we will identify the existent security threats an ad hoc network faces, the security services required to be achieved and the countermeasures for attacks.

Multi-hop Topology Control Algorithm for Wireless Sensor Networks

Topology control is one of the most important research directions in wireless sensor networks. It is also a key to user node energy efficiently, improve network connectivity and robustness, increase network throughput and extend lifetime of the whole network. In this paper, a Multi-hop Topology Control Algorithm, called MTC, was proposed for wireless sensor networks. The core of MTC has two parts as following. Firstly, a topology control algorithm based on Virtual Grid (TCVG) was presented, which takes the residual energy of nodes in consideration for selecting cluster-heads in virtual grids so that the node with most residual energy would become cluster-head. In this algorithm, cluster-head uses single-hop to communicate with sink. By simulation it has verified the TCVG algorithm having more obviously improvement on the network performance, comparing with the algorithm for GAF. Secondly, the algorithm of the TCVG algorithm is improved in cluster data transmission phase after the cluster heads are selected, called MTC, which can be used multi-hop in large scale. In the algorithm, it makes the equal distributed cluster-heads of the network into constructing a routing tree by means of the multi-hop transmission way so that this may reduce the number of cluster head nodes, when it communicates directly the base station (BS). In this algorithm, all nodes are homogeneous and have the same initial state; they are distributed according to certain rules in the monitoring area. The same as former algorithm, this algorithm also divides the entire network into several virtual grids. The topology generation process uses the lowest communicating cost path. When finishing the topology generation, the entire network becomes a spanning tree with lowest consumption. Using Heteropic distribution of sensors solves the hot spot problem efficiently, ensures the network connectivity, and finally achieves an efficient topology control.

Directed Cooperation in Multihop Wireless Sensors Network

Directed Cooperation in Multihop Wireless Sensors NetworkThis paper proposes a relational abstraction for Wireless Sensors Network where node can identify its neighbors around it. Because of limited radio link range only some of nodes have a direct contact with the base station and transmission is carried out in a multihop way so information is send from one node to another towards the BS. We propose a relation π that represents cooperation between nodes and takes advantages of topological properties of the network. Based on the hop-distance from the BS any nodekcan determine a setN&lt;(k) that consists of nodes to which/kshould send messages in order to retain a data-flow direction towards the BS.